Electrohub Flight Characteristics- Throttle response/altitude

[AKCub]

I built an Electrohub up from the show using the kit from ready to fly and I use it for LOS flying to take video. Most of my flying is done in ANGLE mode. I am Using a DX6i radio and AR6210 rx and a 3s 2200 mah battery. Multiwii Flip 1.5 with gps/baro addon. I have balanced the props. I added a voltage readout to backup my timing for flights.

My issue (if it is an issue) is with the throttle response. I can put it at an altitude and it will stay there for a bit but as soon an I try to move the quad I end up chasing altitude. It's not horrible but I get the feeling that it's something I can tune away with settings on the Flip 1.5 board. It might just be the way these things fly though. The tricopter I built didn't seem to have anywhere near this much yoyo effect.

I haven't done anything with the stock PID settings yet. Any advice would be appreciated.

Thanks,

Scott

 

[Random_rc]

looks great but i don't quite get what you mean by chasing altitude

 

[cranialrectosis]

If by 'chasing altitude' you mean the copter gains altitude when you pitch or spin it, your P gains are too high.

When you tip the copter from a level hover, the rotors become less efficient and need to spin faster to keep the copter at current altitude. I manage this manually by bumping the throttle a bit when I spin or tilt the copter.

With a 18 wheeled truck, motorcycle, plane or copter, the throttle is your second most important control (your head is number one). Learning to manage the throttle is key to aerobatics or smooth flight. Throttle management is how Warthox flips a quad 2" off the ground without hitting the dirt.

If the copter is dipping when you spin or tip it, you can adjust P gains a bit if you are adept at flying in acro mode. If you are in your first 5 weeks of flying, I recommend you learn to offset the drop with a touch of throttle. Even if you tune this out later, that skill will be valuable later.

 

[joshuabardwell]

Especially if you are flying in Angle mode, I would guess that what you are describing is related to piloting skill. There is nothing wrong with flying in Angle mode, but flying in Acro mode sort of forces you to be more actively involved with the piloting, which tends to hone your skills a bit more.

Think about the force vectors acting on a copter when it is hovering. Gravity is pulling down with acceleration G. The props are pushing up with acceleration A. Since you are hovering, A = G.

Now imagine that you pitch forward to begin flying that direction. If you leave the throttle in the same position, A still equals G, but A is no longer pointing straight down. Break A down into its horizontal and vertical components. For simplicity, let's say you pitched to a 45 degree angle. So now you have A/2 pushing you forward, and A/2 pushing you upward. Now the vertical component of A is only 1/2 of G, so your copter will descend. In order to maintain altitude, you would need A = 2G, so that the vertical component, A/2 would be equal to G.

Long story short, flying a copter involves constant throttle adjustments to maintain altitude. As you get more experienced, you will find it second nature to put in a little extra throttle when you pitch or roll, and to take out a little bit of throttle when you level out again. If you practice flying in Acro mode, this will become more second nature, since leveling out the throttle will be something you have to actively do, instead of something the FC does for you.

 

[CrashRecovery]

Don't forget that when ever you tell the quad to move motors speed up and others slow down. Throttle control will help with your issue

 

[dfrogy]

are the motor ready to fly eletrohub Witespy Red Special Motor.

 

[earthsciteach]

The Electrohub is VERY light. It doesn't take much to make it gain altitude.